It is known in the art that adding wheels to portable containers, especially luggage, provides significant mobility improvements over non-wheeled containers. Even a very brief observance of an airport or train station demonstrates consumer preference for wheeled luggage. Including a pull bar and handle aides the operator of the portable container in maneuvering the same. The pull bar typically extends out from the container and thereby provides at least two advantages. The pull bar extends the handle up to a height of the operator's hand thereby removing the need for the operator to hunch or bend to reach the container. Additionally, a pull bar allows for the portable container to trail behind the operator providing clearance from the operator's legs and feet.
Many portable container designs, especially those for luggage, include two wheels disposed along a lower edge of the container. In such configuration, the container must pivot about the wheels and maintain in an angled position during transit to ensure that no portion of the container drags along the ground surface. The natural pendulum effect of human locomotion can result in a continuous oscillation of the pivot angle. The oscillation can result in shaking of the container and the contents therein. The oscillation can be prevented with additional manual intervention by the operator, and the additional manual intervention can be difficult for the operator to maintain over a long period of time.
Many portable containers with semi-rigid walls retain their shape even when empty. The internal void of a container can consume a significant volume of storage space. While other items could be stored within the container, this could increase the time required to pack, unpack, and store the container.
The pull bars of the portable containers are often stored by sliding into the body of the portable container against one of the side walls, which reduces the internal capacity. In such configuration, the location to stow the pull bar is inflexible.